"Some people believe football is a matter of life and death, I am very disappointed with that attitude. I can assure you it is much, much more important than that". Bill Shankly
"You're playing worse and worse every day and right now you're playing like it's next month".Herb Brooks

I think Vol'jin, Lor'themar, Saurfang and Jaina should fight him at the same time.

Everyone should get a shot, but given the volatile magics that he controls, Jaina seems like the one that could finish him; I think that you kinda have to kill him on a magical way (Arcane Implosion? teleport him to the twisting nether?)

I wish there was another alliance character to fight him, but you can put Varian in there; it would be dangerous to put the leader of the alliance on such a perilous situation. There aren't a lot of alliance leaders personally victimized by Garrosh.

Mmmm, you could put Anduin, but one, would Varian let him (no) and would Anduin be reckless like that? he is the heir to Stormwind. Also two humans make the rest of the alliance look bad. Tyrande is the only other leader that Garrosh has crossed, but it was never in person, and nothing that intimate. Vereesa? she would be reckless enough to go, but she isn't even a playable faction leader.

Hope they can up the cut scene where he dies, maybe show him burned, scorched, pierced by arrows and bullet holes. Someone person comes along and coup de grace his head of his shoulders to mount on a pike.

You're a fine example of how gamer communities have become infested with endlessly whining and bitching, arrogant, opinionated, unreasonable, all the way immature, completely delusional, tendentially psychotic, insulting individuals one really doesn't want to be linked with. And playing with you guys is certainly no fun at all. I don't know where this kind of folks spawns from. Must be a nest somewhere ...

Players get Garrosh down to .01% health and before we're able to deliver the killing blow, a piece of authentic Orgrimmar roof falls on Garrosh and crushes him to death. In the final cinematic we see his little orc feet, which are sticking out of the rubble, shrivel and curl up.

it could be thrall or horde leader who killed him
if it thrall = no orc can get angry at other horde races
if it was horde leader = no horde can get angry at alliance
but if it was alliance leader = horde faction and player will rage at alliance

Players get Garrosh down to .01% health and before we're able to deliver the killing blow, a piece of authentic Orgrimmar roof falls on Garrosh and crushes him to death. In the final cinematic we see his little orc feet, which are sticking out of the rubble, shrivel and curl up.

I find this to be very likely, to be honest. I can just see him looking up with his tiny little red/purple eyes wide in realisation... and splat.